The Australian Sex Party has threatened Google with legal action after the search engine refused to run its ads on the eve of tomorrow's Melbourne by-election.

It comes after Sex Party ads were blocked by Google at the last federal election because the company — which is typically opposed to censorship — perceived the text as too racy (the ads were reinstated by Google the day before the election).

Sex Party candidate Fiona Patten said this time the search giant said it would not approve her ads "because we have a donate button on our page and we're not a charity".

Don't all political parties allow donations? Is google imposing it's own sense of morality onto australian politics?